In the first case Jesus was supplying a shortage in a wedding celebration, in the second case Peter was advocating the use of a little wine as medicine. Both are exceptional cases which do not go beyond the parametre of the general rule which prohibits drunkenness (Gel. 5:19-21).
Drunkenness debases a person (Gen. 9:21) provokes brawling (Prov. 20:1), causes poverty and drowsiness (Prov. 23:21), perverts justice (Is. 5:2223) and confuses the mind so that it is unable to take a right judgment (Is. 28:78). It leads to licentiousness and lewdness (Rom 13:13), and disorderliness (Mt. 24:48-51) in life. It is a hindrance for our watchfulness for the Day of the Lord (1 Thes. 5:6-7). There are some instances in the Bible which depict clearly the evil caused by drunkenness. Ben-Hadad and his companions had to face defeat in the battle due to their drunkenness (I Ks. 20: 16-21). King Ahasuerus had to face degradation since his queen refused to come before him since he was drunk (Esther 1 :9-11). Belshazzar's drunkenness seems to be the cause of his debauchery (Dan 5:1-4). Oppression of the poor and the needy seems to bathe offshoot of women's drunkenness (Amos 4:1). Drunkenness seems to have been the cause of disorderly behavior by some, in the Lord's supper (1 Cor. 11 :20-22).
For a son who is disobedient and drunkard OT advocates capital punishment (Deut 21 :20-21). However, Paul advocates only ex-communication from Christian fellowship for such people. "But I have written to you not to company with anyone named a brother, who is a fornicator, or covetous, or idolater, or a reviler, or a drunkard, or an extortioner - not even to eat with such a person" (1 Cor 5:11). Because Paul is sure that these people would be excluded from the Kingdom of God. "Do you not know that the unrighteous will not inherit the Kingdom of God? Do not be deceived. Neither fornicators, nor idolaters, nor adulterers, nor homosexuals, nor sodomites, nor thieves, nor drunkards, nor revilers, nor extortioners will inherit the Kingdom of God" (1 Cor 6:9-10).
Hence the Christian doctrine on addiction to liquor is quite clear.